Without limiting the scope of the invention, its background is described in connection with the use of light therapy to stimulate cerebral hemispheres, as an example.
Light has been shown to effect the stability of a person's energy, mood, sleep, concentration and the regulation of a person's circadian rhythms. Light deprivation, for example, has been shown to cause fatigue, irritability, anxiety, weight gain, social withdrawal and a lack of alertness.
The human brain produces detectable signals that vary in strength and frequency over time. These signals are detectable as electromagnetic waves, and vary from one part of the brain to another and may, in fact, vary over time. Electromagnetic waves with different frequencies are associated with different moods and mental abilities. For example, a brain frequency of 13 Hertz or higher is known as a "beta rhythm" and is normally associated with daylight activity when all five sensory organs are functioning. In contrast, a brain wave with a frequency of 8-13 Hertz is known as a "alpha rhythm" and is often associated with a relaxed creative state. Brain waves known as "theta rhythm" and "delta rhythm" have frequencies of 4-8 Hertz and 0.5-4 Hertz, respectively. Theta-rhythm abnormalities have been associated with learning disorders in adolescents. The delta-rhythm is generally found in normal sleep.
It is generally believed that a person afflicted with a sleeping disorder has problems generating a delta rhythm. In contrast, people who have difficulties learning or display behavioral problems that affect learning, have problems associated with abnormalities of the alpha rhythm. These rhythms have been found to be regulated by brain biochemistry.
Two biochemical compounds have been implicated in the control of brain patterns and rhythms: melatonin and serotonin. Melatonin is a metabolite of serotonin, and is synthesized by the pineal gland. The production of melatonin from the pineal gland is stimulated by the sympathetic neural output of the supra chiasmatic nuclei. Production of melatonin serves as an internal body clock that is regulated by the light-dark cycle, as sensed by the visual system. As light enters the eye, the reticulo-hypothalmic tract synchronizes the suprachiasmatic nuclei using biochemical neurotransmitters such as melatonin. Attempts at changing brain biochemistry however, are greatly limited by the side-effects exhibited by most therapeutic drug regimens.
The use of light therapy, unlike drug therapy, has been used to treat patients that have been afflicted with a seasonal affective disorder. U.S. Pat. No. 5,562,719 to Lopez-Claros describes one such method for treating seasonal affective disorders that relies on preferential light stimulation in a hemifield pattern only affecting one quadrant or 50% of the non-dominant cerebral hemisphere. Seasonal affective disorder is a condition that affects from 5-20% of the population in areas with decreased year time light levels, such as the Northern Hemisphere. A common treatment for seasonal affective disorders is the use of lamps or light boxes that provide between 2,500 to 10,000 lux illumination in a hemifield pattern only affecting the inferior quadrant or 50% of the non-dominant cerebral hemisphere. This level illumination is an attempt to stimulate summer-like light levels. The Lopez-Claros patent is directed to the stimulation of one cerebral hemisphere to a greater degree than the other, thereby treating seasonal affective disorder by preferential light treatment. The Lopez-Claros invention, however, stimulates only one quadrant of the optical axis or 50% in both eyes thereby precluding its use in the stimulation of a hemisphere wholely.
As apparatus and method for treating an individual by electroencephalographic disentrainment feedback is the focus of U.S. Pat. No. 5,365,939 issued to Ochs. Electroencephalographic disentrainment feedback involves measuring a patient's brain waves, and based on those brain waves, generating impulses that disrupt brain waves by "disentraining" brain waves that are "entrained" or entrenched in the brain. By "disentraining" the entrenched brain waves, a patient's sub-optimal post-traumatic neural functioning is restored. The apparatus, however, requires the supervision of a doctor, as people with hypersensitivity may require that treatment be immediately stopped. The increased supervision makes the cost of use very great and eliminates its portability.
A slight variation from the Ochs patent, is U.S. Pat. No. 5,036,858 issued to Carter and Russell, that involves using two frequencies, with a slight frequency differential between the two frequencies, to change a patient's brain waves. In this patent, the patient's brain waves are also measured, and based on these measurements, disruptive brain impulses are generated that disrupt the patient's brain waves in a constant feedback mechanism.
What is needed is a simplified apparatus and method that enhances the innate abilities of individuals with learning disorders. The apparatus and method must also be simple to use, inexpensive and portable, in order to provide for greater distribution to those most in need of enhanced learning abilities. Individuals who would benefit the most from an inexpensive, simple to use device that increases learning abilities are the poor in urban inner cities and in rural areas. More specifically, what is needed is a simple, inexpensive device that can be used by elementary and secondary school children whose parent, or guardian, can ill afford expensive drug or light treatments requiring medical supervision. Others that would benefit from such an apparatus and method are athletes, business people, and academicians.